Explosive-engine.



PATENTED JAN. 24, 1905.-

J. G. CALLAN.

BXPLOSIVE ENGINE.

APPLIOATION FILED SEPT.

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PATENTED JAN. 24, 190,5.

J. G. GALLN.

EXPLOSIVE ENGINE.

APPLIGATION FILED sEPT.4. 1903.

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llllllllllllllllllllll" IIUIIIIIIIIIIIIIV No. 780,549. PATENTED JAN.24, 1905.

J. G. CALLAN.

EXPLOSIVE ENGINE.

APPLICATION FILED SEPTA. 1903.

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Invent@` John G. Callarw.

Patented January 24, 1905.

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JOHN G. OALLAN, OF LYNN, MASSACHUSETTS, ASSIG-NOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEV YORK.

EXPLOSlVE-ENGINE.

SPECIFOATION forming part of Letters Patent No. 780,549, dated. January 24, 1905.

Application filed September 4, 1903. Serial lilo.l 171,865.

Be it known that I, JOHN G. OALLAN, acitizen of the United States, residing' at Lynn, county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Explosive-Engines, of which the following is a specification.

This invention relates to a balance-piston double-cylinder gas or internal-combustion engine operating on the two-cycle principle. It relates particularly to an engine wherein coacting pistons receive equal and opposite impulses 'from a common explosive charge of combustible gas and in which two sets of such oppositely-acting pistons receive alternate power impulses, their rectilinear motion bcing translated into rotary motion of a crankshaft disposed centrally of the pistons.

The object of the invention is to provide a simple and symmetrical arrangement and organization of thc operative parts of the engine by which a well-balanced action is obtained, reducing vibration and evenly distributing the power of the impulses, as will be more fully described hereinafter and particularly pointed out in the claims.

In the accompanying drawings, Figure l is a horizontal longitudinal section of my iinproved engine, showing parts thereof in plan. Fig. 2 is a side elevation of the engine, showingI a part section of a piston-cylinder and cross-head guide. Fig. 3 is a vertical longitudinal section taken centrally of the engine. Fig. 4 is a semisection end elevation of the engine, the section being' taken through the crank-chamber, a cross-head guide, and the parts contained therein. Fig. is a vertical transverse section on line 5 5, Fig. l; and Fig. 6 is a similar section taken online 6 6, Eig. 2.

Similar reference characters indicate corresponding parts.

The fundamental principles that underlie the mode of operation andthe novel features of construction by which my invention is carried out may be stated in a general manner, as follows: employing a charge of explosive gas in a cylinder to act with equal and opposite Vforce upon two coacting` pistons, or, in other words, establishing a balance of the energy of explosion of a combustible gas relatively to two pistons; using two sets of such pistons and two cylinders, one cylinder for each set of pistons; connectingcorresponding pistons of both cylinders with an oscillating cross-beam,\vhereby reciprocating rectilinear motion of the pistons is translated into oscillatory motion; employinga central compound `crank-shaft having symmetrically oblique crank-pins, upon which latter' the oscillating cross-beams are mounted,'and alternating the explosions in the cylinders whereby the pistons cooperate to oscillate the cross-beams, which in turn impart their motion to the oblique crank-pins, to the end that rotary motion is imparted to the crank-shaft.

As shown in the drawings, the-casing of the engine comprises three main sections-M namely, a crank-shaft frame A, piston-cylinders B, and cross-head guides O. The crankshaft frame A extends centrally of the engine and is flanked on either side by the pistoncylinders B, arranged parallel to the axis of the crank shaft frame. The cross -head guides4-four in numberhare disposed in axial alinement with the cylinders and one 'at each end thereof.

The main motive parts of the engine consist of a compound crank-shaft l, itself comprising end and middle shafts 2 and 3, crankdisks 4, and symmetrically oblique crankpins 5, cross-beams 6, arranged on said crankpins, trurmion-boxes 7 for the cross-beams, cross-heads 8, piston-rods 9, and the pistons 10.

The crank-shaft frame A consists of two castings substantially similar in form and each constituting half of the frame, being separable on a horizontal plane. In the plane of separation of the two-part frame Athe upper and lower castings are formed with end half-bearings 11 and central bearings l2, and within these bearings are provided bushings 13. Crank-chambers 14 and 15 are arranged intermediate of the central bearing and end bearings, and in each of these chambers is contained a cross-beam 6 and its trunnion-box 7, also the crank-disks 4 and the crank-pin 5. The chambers form closed-in compartments,

which serve the function of admission-chambers, the chamber 14 providing for the admission of atmospheric air and the chamber 15 for the admission of the explosive mixture from a suitable carbureter. The crank-shaft frame A is further provided with compression-chambers 16 and 17, into which, respectively, air from the crank-chamber 14 and explosive mixture from the crank-chamber 15 is inducted and compressed, as will be explained hereinafter. The air-compression chamber 6 is cored out in the upper casting of the frame A, and the mixture-compression cham ber 17in the lower casting of said frame, each chamber being provided with a perforated reinforcing-web 18, as shown in Figs. 3 and 6, and extending between the crankchambers 14 and 15.

The two castings of the frame A are bolted together, as at their ends, by bolts 19 and at intermediate points by through bolts 20, which latter bolts extend through cored-out vertical' columns 21. The columns of one semicasting register with those of the other semicasting of the crank-shaft frame A, as shown clearly in Fig. 6.

The piston-cylinders B are assembled in close proximity to each other on opposite sides of the frame A in order to reduce the transverse dimension of the engine, and to fulfil this purpose each casting of the crankshaft frame converges -at the compressionchambers toward the central shaft-bearing 12.

The piston-cylinders are of the jacketed type, comprising symmetrical castings, and each has a bore of the same diameter throughout its length. The space between the inner cylinder-wall 22 and the jacket-wall 23 of each piston-cylinder is divided into annular passages or spaces by solid partition-walls 24. Of these passages or spaces 25 is the passageway for the combustion mixture, 26 the passage for air, 27 the water-space, and 28 the passage for the exhaust. The water-space 27 extends, preferably, the full length of the working portions of the piston-cylinders and also surrounds the exhaust-passages 28, so as to effectively cool those portions of the cylinders subjected to the greatest intensity of heat. The water-spaces have a commonsupply and a common discharge connection in a suitable circulating cooling system. To this end the upper casting of the crank-shaft frame is formed with a transverse chamber 29 at one end, that communicates with the Water-spaces of the jacleted cylinders through opening 30, as shown in Figs. 2 and 3. This chamber or compartment 29 is provided with a threaded bossed opening 31 for pipe connection. The lower casting is also. provided with a transverse compartment 32, that communicates with the Water-spaces of the piston-cylinders through openings 33, one of which latter is shown in Figs. 2 and 3. Provision is also made to form pipe connection with the inders.

compartment 32, as by -a threaded bossed opening 34. Thus it will be understood that in the circulating system the cooling medium enters the compartment 29, wherein it branches in its course, passing to and through the water-spaces 27 around lthe piston-cylinders and thence discharging into the lower compartment 32, from which it passes, cornpleting its'circuit in the cooling system in any approved manner.

The mixture-passage 25 and the air-passage 26 are arranged at the end of the working portion of each cylinder B opposite to that of the exhaust-passage 28. An annular row of admission-ports 35 admits air to the cylinders, as does also an annular row of ad mission-ports 36 admit the explosive Imixture at a definite stage in the cycle of operation of the engine, as will be set forth hereinafter. Exhaust of the spent gases of combustion is had through a partial annular row of oblique exhaust-ports 37. The air-passages 26 and the mixture-passages 25 are in constant communication with the compression-chambers 16 and 17, respectively, through openings 38 and 39, as seen in Fig. 6. The exhaust-passages each expand into an enlarged portion 40, and to a large extent the exhaust-ports 37 open directly into these enlarged portions, which affords ample space by which a rapid scavenging can take place. These enlarged portions 40 manifestly have means fordischarging the burned gases, consisting, preferably, of openings in their bottoms, but which are not shown in the drawings, and any suitable arrangement may be provided for connecting these discharge-openings to a common mufl'ling device.

The cross-head guides C are also castings, preferably cylindrical, and all made after one pattern. They are arranged one at each end of the ,piston-cylinder B, having their axes in alinement with the axes of the piston-cyl- These cross-head guides are each formed with a circumferential flange 41, extending partially around the same and a suitable distance from one end. A plate 42 is formed at one side of the cylindrical body of the cross-head guide, by means of which and the circumferential iiange 41 the cross-head guide is secured tothe crank-shaft frame and the cylinders. The cross-head guides C are secured to the crank-shaft frame A and the cylinders B by means of bolts 43,'thus forming the complete casing of the engine. The outer end of each cross-head guide is closed by a screw-cap 44, and the inner end is cast closed, except for a stuiiing-box 45. These inner ends of the cross-head guides project into the cylinders, forming internal heads. The plate sides of the cross-head guides are slotted to provide elongated openings 46, which are disposed opposite to corresponding openings 47 in the crank-chambers and through which the extremities of the oscillating cross-beams extend'.

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Considering now in detail the various working parts of the engine, the crank-shaft 1 is a compound structure composed of a middle section and end sections. The middle section is a shaft 8, comprising a spool-shaped forging having' heads 4S at its ends. The end sections are also drop-forgings, each comprising a shaft 2, double cranks 4C, and a crank-pin 5. The cranks may be in the form of arms or disks, and they are displaced around the axis of the shafts 2 at an angle of one hundred and eighty degrees. Each crank-pin between its cranks is disposed obliquely, with its center in line with the axis of rotation of the cranks. The three sections of the crankshaft are connected axially in alinement and with the crank-pins 4 symmetrically disposed relative to each other. By means of this construction each crank-pin describes in rotation a double conical path about a central point of intersection of the axis of the crankpin and the axisof the crank-shaft. The sections of the crank-shaft l are securely connected together, the inner crank-disk of each end section being keyed to the heads of the middle section by means of diametrical doubledovetailed keys 4:9; but any suitable mechanical equivalent may be employed for this purpose.

As previously stated, the cross-beams 6 are arranged in the crank-chambers. They are assembled on their respective crank-pins, and each cross-beam is forged in two parts, divided longitudinally. A central elongated bearing-box 50 is provided on each crossbeam, extending,l at right angles to the axis thereof, and the same being separable with the two parts of the cross-beam and preferably integral therewith. Split bearing-sleeves 5l are seated in the boxes 50, and the two parts of each cross-beam are secured on their crank-Inns by screw-bolts 52. These elongated bearing-boxes afford large bearing-surfaces on the crank-pins and also form large working bearings for themselves in the trunnion-boxes T, in which they are assembled.

The positive motion of the cross-beams is oscillatory, and to enable this motion to be imparted to them they are each assembled in a trunnion-box 7. The trunnion -boxes are each formed of halves, which are secured rigidly together by screw-bolts 53. To permit oscillations of the trunnion-boxes, each half thereof is forged with a trunnion 54, disposed vertically at right angles to the plane of the oscillation of the cross-beam. These trunnions 54 are journaled in suitable bearings 55, cast in the crank-shaft frame A, the bushings 5G being provided for said trunnion-bearings 55. The trunnion-boxes are provided with ways 57, through which the crank-pins and bearing-boxes extend, and in order to provide for the double conical path of rotation or wabbling movement of the crank-pins and bearing-boxes the ways of each trunnion-box are divergent or flaring outwardly from the center in opposite directions, as shown in Fig. 3. These flaring ways 57 serve as guides in which the bearing-boxes work during their movement and transform their wabbling motion to rotary motion of the crank-pins and thereby to the crank-shaft.

In addition to the oscillating motion of the cross-beams about the axes of the trunnionboxes there is imparted to each cross-beam a minor oscillating motion simultaneously with the main oscillating motion. This minor oscillating motion is due to the rocking of the bearing-boxes 50 in the double flaring ways 57k incident to the wabbling movement of the crank-pins. To provide for this minor movement, the cross-beams are of circular crosssection and bear in bushings 56 of the trunnion-boxes. i

The pistons 10 are of the hollow type, threaded on their piston-rods 9 and secured by nuts 58. The cross-heads 8 are cylindrical and are formed integral with the piston-rods axially in line therewith. The outer portions of the cross-heads are hollow and contain universal connections between the cross-beams and the cross-heads. Each cross-head carries a ball 59, seated between a concave bearing-block 60 and a bearing-cap 61, having a concaved portion for the ball. The caps 61 screw into the outer ends of the cross-heads and may be adjustable, so as to compensate for wear of the bearings. The balls 59 arebored for receiving the extremities 62 of the cross-beams and in which the latter advance and recede during the rectilinear movement of the crossheadsin chordal relation to the arcs of oscillation of the cross-beams hereinbefore referred to simultaneously with the advancing and receding motion they possess. The crossheads on opposite sides of the balls 59 are slotted to provide openings 68 obviously for the purpose of receiving the ends of the crossbeams.

The inner ends of the cross-head guides form cylindrical flanged portions that pass into the internal heads of the cylinders C at the limit of the instrokes of the pistons, while the hollow pistons themselves pass into the space around the internal portions of the cylinderheads at the limits of the outstrokes. By means of this telescoping relation of the crosshead and the piston with the internal cylinderheads large bearing-surfaces are provided, while at the same time there is an economy in weight and size of the parts and total length of the engine. The spaces between the pistons and internal cylinder -heads are placed in periodic communication with the crank-chambers by suitable valve mechanisms-that is to say, upon their instrokes the pistons operate to produce suction from the crank-chambers and upon the outstrokes of the pistons the communication previously established with the crank-chambers is cut otl by the Valve TOO IIO

mechanisms and the contents of the spaces behind the pistons is transferred and compressed into the compression-chambers. The pistons at the right end of the engine produce the suction of air from the crankchamber 14 through openings 64 and 65 and in turn transfer or pump it into the compression-chamber 16 through the passages 66 and 67 and valves 68 and 69, as seen clearly in Fig. 5. The pistons at the left end of the engine subserve the same function as the others, except that they draw fuel charges into the crank-chamber 15 and also from the same through passages 7() and 71 and transfer the charges into the mixture-compression chamber 17 through similar passages 7 2 and 7 3 and valves 74 and 75, as shown by dotted lines. The crankchambers 14 and 15 are provided with threaded openings 76 and 77, which are intended to be supplied, respectively, with a suitable air-admission valve (not shown) and with a fuelsupply pipe from a suitable carbu reter. (Not shown.)

As the pistons of one cylinder alternate in the direction of their strokes with those of the other cylinder, producing thereby alternate suction and pumping of the charges of mixture and of air, a common rotary valve may be provided to control the passage between each crank-chamber and the adjacent suction portions of the cylinders. Thus a rotary valve 78 controls the air-passages 64 and 65, while a rotary valve 79 controls the mixture or fuel-passages and 71. These valves are of duplicate construction and each consists of a cylindrical body, one being secured on each head 48 of the middle section of the crank-shaft 1, so as to rotate therewith. Each valve is provided with a frusto-conical bearing portion which rotates upon a similarlyshaped valve-seat 80, suitably secu red in the crank-shaft frame A. The valves are retained on the seats 80 by the tension of spring 81, interposed between the heads 48 of the middle section of the crank-shaft and interior collars 82, threaded in the inner ends of vthe valves. One air-passage is arranged diametrically opposite the other air-passage, and the mixturepassages are similarly arranged. The valveseats are provided with openings corresponding in position with these passages. The function of each rotary valve is to keep one of its respective passages open during half a revolution while its other passage is closed, or vice versa. To this end the valves are each provided with a semi-annular slot 83 in the frustro-conical portion thereof. vThe valves are securedl to the crank-shaft in such relation to the passages 64 65 and 70 7l that they are adapted to open the passages simultaneously with the beginning of the suction-strokes of the pistons, remaining open during their full suction-strokes, and also to close simultaneously with the return or out strokes of the pistons and remain closed during the entire out strokes. As the valves 7 8 79 prevent the return to the crank-chambers of the charges drawn into the suction portions or chambers of the cylinders, the charges find outlet under compression of the outstrokes of the pistons through passages 66 67 and valves 68 69 in the case of the air charges and through passages 72 73 and valves 74 75 in the case of the full charges, respectively, into the aircompression chamber 16 and the mixturecompression chamber 17, as hereinbefore mentioned. These latter valves open inwardly into the compression-chambers, and they are of common check-valve construction, removably secured in the crank-shaft frame, having seats in webs 84. of said frame, as seen in Fig. 5.

To effect the explosive ignition of the charges in the cylinder, any suitable ignition device may be employed; but, as shown, a jump-spark plug 85 is provided for each cylinder. The spark-plugs are each carried in a reversible plate 86, bolted to the cylinders in elongated openings 87. By means of reversing the plates 86 the position of the sparks may be adjusted either to a point central between the pistons or adjacent to the pistons that uncover the admission-ports to admit the charges, rlhis adjusting of the position of the spark-plug, and thereby the sparking terminals thereof, enables a close approximation of position to the Zone of uniform carburization of the gas and air in the cylinders, so as to obtain the best ignition effect of the explosive mixture.

In vew of the foregoing description the operation of the engine will be understood to be as follows: Motion is imparted to the operating parts in the usual manner by any manually-operated means, such as a starting-crank on the crank-shaft, until the engine takes up its cycle. each cylinder of the engine except that the explosions alternate with each other in point of time, or one explosion takes place at one hundred and eighty degrees in advance of the other,there being two explosions for each revolution of the crank-shaft. While the cycle of operation in one cylinder is-independent from that of the other cylinden'the compressionchambers are Ain common relation to the two cylinders, thereby obviating the necessity of two separate compression-chambers for each cylinder of the engine. Considering the parts in the cycle of operation inv one cylinder only, the initial instrokes of the pistons draw in a charge of air at one end of the cylinder and a charge of fuel at the opposite end, the rotary valves being open during these induction-strokes. Upon the return or out strokes the charges in the suction portions or chambers of the cylinders are transferred by the action of the pistons into their respective com- The cycle of operation is the same in IOO IOS

pression-chambers, compressing the charges therein to the pressure usually employed in two-cycle engines. Also near the ends of their outstrokes the pistons uncover the exhaust and admission ports to scavenge the spent gases and to admit fresh charges. The charge of air is admitted in advance of the charge of fuel by reason of the air-admission ports uncovering slig'htly before the uncovering of the fuel-admission ports, the admission of the charges being under their own pressure. The next instrokes of the pistons simultaneously compress the charges of air and fuel mixture in the cylinder between the approaching pistons and draw new charges of air and fuel mixture into the suction-chambers of the cylinders. At timed intervals explosive ignition of the compressed mixture is effected, as will be obviously understood, imparting equal and opposite power impulses to the pistons. The products of combustion exhaust at the uncovering' of the exhaust-ports under their expansive pressure and aided by the admission of a charge of air through the air-admission ports slightly after the beg'inning of uncovering of the exhaust-ports. The charge of air displaces the burned gases and practically completes the scavenge of the cylinder and establishes a clean cylinder of air for the inhaust of the fuel charge. The fuel charge is preferably insufliciently carbureted when admitted to the cylinder and depends upon further mixture with the air in the cylinder for its complete carburization. In order to prevent any tendency to stratification of the air and fuel, the piston-nuts on the pistons that uncover the admission ports serve as baiiies that defiect the charges upon their being admitted to the cylinders, causing' their agitation and thorough mixing. The piston-nuts are also rounded ofi', so as to opfer no retarding portions to interfere with the motion of the air and fuel in the process of mixing or to form pockets for the lodginent of unmixed gases. The operation of the engine will thus be understood to embody the wellknown two cycle principle, modified slightly, however, in respect to the scavenging of the products of combustion by a charge of air as preliminary to the admission of the fuel charge. Alternately-explosive ignitions of the charges in the cylinders impart corresponding power impulses to the two sets of balanced pistons, whose motion is translated through the cross-heads into oscillating motion of the cross-beams, which latter in turn rotate the central crank-shaft, their oscillating motion being' translated into rotary motion by means of thc symmetrically oblique crank-pins.

The arrangement and organization of the operative parts provide a smoothly-running engine with a large turning' movement of the crank-shaft and combines in its construction compactness, symmetry, and balance of its parts. by reason of which the vibrations common to internal-combustion engines are reduced to a minimum.

In accordance with the provisions of the patent statutes I have described the principle of operation of my invention, together with the apparatus which I consider to be the best embodiment thereof; but I desire to have it understood that the apparatus is only illustrativc and that the invention can be carried out by other means.

Vhat I claim as new, and desire to secure by Letters Patent of the United States, is-

l. In an engine, the combination of arotary shaft, a plurality of cylinders arranged in parallel relation to said shaft, a pair of balanced pistons in cach cylinder, and means for imparting rotary motion to the shaft from the pistons.

2. In an engine, the combination of a central shaft, a plurality of cylinders disposed on diametrically opposite sides of said shaft in axial parallel relation thereto, a pair of balanced pistons in each cylinder, and means operatively related to said pistons for imparting' rotary motion to said shaft.

3. In an engine, the combination of two sets of balanced axially-alining pistons, a rotary shaft between said pistons in parallel relation thereto, and in a common plane, and means on said shaft for converting the rectilinear reciprocating motion of said pistons into rotary motion of said shaft.

4. In a balance-piston engine, the combination with a rotary shaft having' symmetrically oblique crank portions, of oppositely-actingV pistons movable rectilinearly in parallel directions to said rotary shaft, and means opei'atively related to said pistons and symmetrically oblique crank portions for rotating said shaft.

5. In a balance-piston engine, the combination with a rotary crank-shaft, of oppositelyacting pistons arranged on opposite sides of said crank-shaft, and universally-movablc means interniediate said pistons and operating with said crank-shaft for converting the reciprocating motibn of said pistons into continuous rotary motion of thc crank-shaft.

6. In a balance-piston engine, the combination with a central crank-shaft having symmetrically oblique crank-pins,of two sets of coacting' pistons, oscillating members arranged on said crank-pins, and universal means connecting' said pistons and oscillating members.

7. In a balance-piston engine, the combination with a central crank-shaft having symmetrically oblique crank-pins, of coacting pistonsreciprocating in parallel direction to said crank-shaft, oscillating cross-beams mounted on said crank-pins, cross-heads, and universal connections between said cross beams and cross-heads.

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8. In a balance-piston engine, the combinal tion with a central crank-shaft having -symmetrically obliquecrank-pins, of two sets of coacting pistons, cross-heads rigid therewith, cross -beams movably connected with said cross-heads, and trunnion-boxes for mounting said cross.- beams in cooperative relation to said crank-pins.

9. In a balance-piston engine, the combination with acentral crank-shaft having symmetrically oblique crank-pins, of two sets of pistons reciprocating' in a direction parallel to said crank-shaft and disposed between said crank pins, cross heads, oscillating crossbeams on said crank-pins movably connecting said cross-heads, and trunnion-boxes for said cross-beams.

10. In a balance-piston engine, the combination with a central shaft having an oblique crank portion, of pistons arranged on opposite sidesof said shaft, cross-heads for said pistons, a cross-beam connecting said crossheads, a central bearing-box carried on said cross beam forming the bearing for said crank portion, and a trunnion-boX having an oppositely-diverging way for receiving said bearing-box.

1 1. In an engine, the combination with a central shaft having an oblique crank-pin, of pistons disposed on opposite sides of said shaft in axial parallel relation thereto, cross-heads for said pistons, a cross-beam formed with a central bearing-box at right angles thereto, said cross-beam and bearing-box being longitudinally separable for assembling on said crank-pin, and a two-part trunnion-boX having an oppositely-diverging way for receiving said bearing-box. l

12. In an engine, the combination of acrossbeam, reciprocating pistons, cross-heads, piston-rods integral with said cross-heads, and rigid with said pistons, and means in said cross-heads permitting universal movement of said cross-beam.

13. In an engine, the combination of a central shaft, pistons operating in parallelism to the aXis of the shaft, an oscillating crossbeam mounted on the shaft, reciprocating cross-heads for the pistons,`said cross-heads each comprising a body, a bearing ball mounted therein and engaging the cross-beam, and bearings for the ball.

14. In an engine, the combination of a central shaft, pistons operating in parallelism to the axis of the shaft, an oscillating cross-beam mounted on the shaft, reciprocating crossheads for the pistons, said cross-heads each comprising a cylindrical body, a bored bearing-ball mounted therein and movably engaging the cross-beam at one end, and bearings for the ball.

15. An engine-casing,comprising a central crank-shaft frame, piston-cylinders'arranged on opposite sides of said central frame in parallel relation thereto, andI cross-head guides arranged at the ends of said piston-cylinders.

16. An engine-casing, comprisinga central crank-shaft frame having crank-chambersat opposite ends thereof, piston-cylinders parallel with said central frame, and cross-head guides carried by said central frame at the ends of said piston-cylinders.

17. An engine-casing comprising` a central crank-shaft frame having crank-chambers at opposite ends thereof, piston-cylinders on 0pposite sides of said central frame between said crank-chambers, and cross-head guides arranged one at each end of said piston-cylinders.

18. An engine-casing', comprising a central crank-shaft frame, crank-chambers provided at opposite ends of said frame, piston-cylinders disposed parallel with Vthe central frame on opposite sides thereof, and cross -head guides arranged at the ends of said pistoncylinders in axial alinement therewith and onk opposite sides of said crank-chambers.

19. An engine-casing, comprising a central frame formed of semisections, crank -chambers provided at the ends of said central frame, piston-cylinders, and cross-head guides.

20. Acasingfor explosive-engines,comprising a central frame formed of separable semisections, crank shaft bearings provided in said semisections, crank-chambers at the ends of said central frame, piston-cylinders secured to said semisections in parallel relation thereto, and cross-head guides at the ends of said piston-cylinders.

21. A casing for explosive-engines,comprising a central frame formed of semisections, crank-chambers at the ends of said frame, a compression-chamber in each of said semisections extending' between said crank-chambers, piston-cylinders carried by said central frame, admissionpassages communicating with said crank-chambers and piston-cylinders, and passages between said compressionchambers and piston-cylinders.

22. The combination ofacrank-shaft frame, a cran k-shaft mounted therein, parallel pistoneylinders, pistons therefor, cross-head guides, cross-heads therein, and cross-beams mounted on said crank-shaft and connected with said cross-heads.

23. The combination of a crank-shaft frame, a crank-shaft mounted therein, piston-cylinders parallel with said frame, pistons therefor', cross-head guides having portions forming internal cylinder-heads, cross-heads contained in said cross-head guides, and cross-beams mounted on said shaft in said frame, said cross-heads and pistons being adapted to telescope with said internal heads.

2li. I n a balance-piston explosion -engine,

the combination of a crank-shaft frame, inde- Y pendent crank-chambers at opposite ends of said frame, compressionchambers, piston- IOO IIO

cylinders, pistons therefor cooperating with the ends of said piston-cylinders to form suction-chambers, passages between said crankchamber and suction-chambers, means for controlling said passages to open and close respectively with the instroles and outstrokes of said pistons valve-controlled, and passages between said compression-chambers and suction-chambers.

25. In a balance-piston explosive-engine, the combination of a crank-shaft frame, independent inclosed crank-chambers at opposite ends of said frame, compression-chambers, a crank-shaft mounted in said frame, pistoncylinders, pistons therefor and forming suction-chambers with ends of the cylinders, diametricallyopposed passages between said crank-chambers and suction-chambers, rotary valves attached to said crank-shaft controlling said passages, independent passages between said compression-cham bers and suction-chambers, and check-valves controlling the same.

26. In a balance-piston explosive-engine, the combination of a crank-shaft frame, a crank-chamber at each end thereof, one of said chambers forming an air-chamber and the other afuel-mixture chamber,independent compressioli-chambers in said frame for air and mixture, a central crank-shaft, pistoncylinders closed at their ends and disposed on opposite sides of said frame in parallel relation thereto, alternately-actuated pistons in said cylinders forming suction-cham bers with the ends thereof, diametrically opposite passages between said crank-chambers and the adjacent suction-chambers` rotary semi-annular valves on said crank-shaft controlling said passages to open simultaneously with the instroles of said pistons and close simultaneously with outstroles thereof, passages connecting the suction-chambers for air with said air-conniression chambers, passages connecting the suction-chambers for mixture with said Inixture-compression chambers, checkvalves in said latter passage leading' to the compression chambers, and independent means communicating between each compression-chamber and piston-cylinder.

27. An engine-casing, comprising a central crank-shaft frame, compression-chambers and crank-chambers provided in vsaid frame, piston-cylinders carried by said frame and provided with water-spaces, a common Watersupply passage in said frame communicating with said water-spaces, and a common waterdischarge passage also communicating' with said water-spaces.

28. In a balance-piston explosion-engine, a piston-cylinder having adjacent to one end air-admission ports and fuel-admission ports, independent passages for said ports, exhaustports adjacent the other end of said pistoncylinder, and an expanded exhaust-passage for said exhaust-ports.

29. In a balance-piston explosive-engine, the combination of a crank-shaft frame, independent compressioli-chambers, piston-cylinders carried by said frame, said cylinders having independent air and fuel admission ports at corresponding ends and exhaust-ports at the opposite ends, oppositely-acting pistons in said cylinders being adapted to open and close said ports for exhausting the products of combustion and admitting the charges.

30. In a balance-piston explosive-engine, the combination of a piston-cylinder having an elongated opening at a medial point, admission-ports adjacent to one end of said cylinder exhaust-ports at the opposite end there of, pistons in said cylinder, a reversible plate secured in said elongated opening, and a spark-plug carried in said plate eccentric to the center thereof.

In witness whereof I have hereunto set my hand this 29th day of August, 1903.

JOHN Gr. CALLAN.

Witnesses:

DUGALD MCK. MoKILLor, JOHN J. IVALK ma. 

